The most Amazing fight would be Garra and Rock Lee hands down, however, this is about the most interesting fight. The most interesting i think would then be Hinata Vs. Neji, because it opened up the characters history and some of the most important basics of Konoha. I am ofcourse talking about the Byakugan and chakra network(which without, any ninja is completely uselss), the family ties and Naruto's will of fire transcending onto others (in this case: Hinata).

Naruto inspires Hinata to fight for herself, and vows vengeance on Neji, and it also gives Naruto his first conflict to solve which can only be done by being a high-ranking ninja (which he isn't at this point), he vows to heal the Hyuuga clan's dynasty and prove that he can change his own destiny. (But this is a whole different fight).